In U.S. Pat. Nos. 3,646,791; 3,731,370; 3,824,824; 3,945,109; 3,961,739 and 3,962,694 assigned to the common assignee hereof there has been disclosed to those skilled in the art of metal forming and tooling how one can utilize a stress wave passing through metal to form, weld, rivet, etc. Such has been there devised to use electromagnetic forces to plasticize metal.
In accomplishing this basic advance in the tooling art it has been suggested by such patents that one uses a capacitor bank to establish a magnetic field in a pancake coil that induces a current in an adjacent driver. The stress wave is thereby generated due to the interaction of the coils magnetic field and that produced by the current to be around the adjacent driver.
Heretofore the pancake coils were unsupported, i.e. they were merely suspended in a plastic. The forces generated tended to fatigue this element. It is due to the need in obtaining a more adequate coil assembly to enable one to have sufficient operational life for stress wave tooling that this invention shall find particular utility.